Methods for detecting photons, radiations or neutrons using superconductors and methods for obtaining two-dimensional images thereof

ABSTRACT

In the improved neutron image detector, MgB 2  enriched in a constituent element  10 B of wide energy gap is used as a neutron detection plate, which is provided at the center and the four corners with a phonon sensor comprising an insulation layer overlaid with Mg 11 B 2  enriched in  11 B of narrow energy gap in order to detect phonons resulting from the generation of α-rays which occurs in the detection plate upon incidence of neutrons, and sensor&#39;s signal intensity and signal propagation time are used to detect the incident position of neutrons.

BACKGROUND OF THE INVENTION

[0001] This invention relates to methods for detecting photons,radiations or neutrons using superconductors and methods for obtainingtwo-dimensional images thereof. The invention is particularlycharacterized by using MgB₂ as a superconductor having isotopes thatbecome adequately superconducting at the temperature of liquid helium.The invention also realizes imaging with high position resolution byusing a two-dimensional imaging method that detects phonons with asuperconductor sensor as they are generated from a superconducting orsingle-crystal detection medium. The invention is therefore applicableto the fabrication of sensors for use in experiments or analyses withphotons shorter than a few microns, X-rays or neutrons. It also findsutility in analytical techniques that take advantage of its ability todetect both the incident energy and position of photons, radiations orneutrons.

[0002] An X-ray detector of high energy resolution using aNb/Al/Al₂O₃/Al/Nb tunnel junction device has been developed by Matsumuraet al. (Matsumura et al., Nucl. Instrum. & Methods, A329 (1993) 227) andother researchers and used as a superconductor-based radiation detector.An imaging detector for detecting the incident energy and position of aradiation with the intermediary of phonons generated from asuperconducting or single-crystal radiation detection medium has beendeveloped by Kurakado et al. (Kurakado et al., Rev. Sci. Instrum. 62(1991) 156) and other researchers.

[0003] In the contemplated prior art technology, Nb has been used as asuperconductor; particularly, in the case of detectors using asuperconducting tunnel junction, it was necessary to cool them to atemperature about a tenth of the critical temperature before use butcooling to about 0.4 K was time-consuming and required an expensiveapparatus. It has therefore been desired to develop a superconductingdetector that can be operated at higher temperatures. In addition,neutron imaging detectors were scanty that used superconductors. What ismore, it has been very difficult to develop an imaging detector capableof detecting X-rays or neutrons at high position resolution.

SUMMARY OF THE INVETNION

[0004] The invention provides a superconducting detector device thatuses MgB₂ with a critical temperature above 30 K which has isotopes ¹⁰Band ¹¹B with different energy gaps. The device has an incomparabledetecting function and can be operated at the temperature of liquidhelium. If MgB₂ is enriched in ¹⁰B rather than ¹¹B, a neutron detectorand a neutron imaging detector can be constructed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]FIG. 1 is a photon and radiation detector using a superconductortunnel junction device that operates on an isotope effect for providingtwo superconductors with different energy gaps;

[0006]FIG. 2 is a neutron detector using a superconductor tunneljunction device which operates on the isotope effect of MgB₂ containingboron as a neutron converter in order to provide two superconductorswith different energy gaps;

[0007]FIG. 3 is a neutron detector having neutron sensitivity only onone side and using a superconductor tunnel junction device whichoperates on the isotope effect of MgB₂ containing boron as a neutronconverter in order to provide two superconductors having differentenergy gaps;

[0008]FIG. 4 is a three-layered neutron detector having neutronsensitivity only on one side and using a superconductor tunnel junctiondevice which operates on the isotope effect of MgB₂ containing boron asa neutron converter in order to provide two superconductors withdifferent energy gaps;

[0009]FIG. 5 is a photon, radiation and neutron detector using asuperconductor tunnel junction device which incorporates a gradientsuperconductor with a gradual compositional transition in the directionof thickness from a superconductor enriched in ¹⁰B of wide energy gap toa superconductor enriched in ¹¹B of narrow energy gap;

[0010]FIG. 6 is a photon, radiation and neutron image detector using asuperconductor tunnel junction device which incorporates as a detectionmedium a gradient superconductor with a gradual compositional transitionin a two-dimensional plane from a superconductor enriched in ¹⁰B of wideenergy gap to a superconductor enriched in ¹¹B of narrow energy gap;

[0011]FIG. 7 is a photon, radiation and neutron image detector using asuperconductor tunnel junction device which incorporates as aquasiparticle trapping layer a gradient superconductor with a gradualcompositional transition in a two-dimensional plane from asuperconductor enriched in ¹⁰B of wide energy gap to a superconductorenriched in ¹¹B of narrow energy gap;

[0012]FIG. 8 is a radiation image detector using a superconductingtunnel junction device to detect the incident position of photons orradiations with the intermediary of phonons generated from an isotopicsuperconductor of wide energy gap as a detection plate;

[0013]FIG. 9 is a neutron image detector using a superconducting tunneljunction device to detect the incident position of neutrons with theintermediary of phonons generated from a ¹⁰B enriched isotopicsuperconductor as a neutron detection plate;

[0014]FIG. 10 is a neutron image detector using a superconducting tunneljunction device to detect the incident position of neutrons by means ofa three-layered superconducting sensor with the intermediary of phononsgenerated from a ¹⁰B enriched isotopic superconductor as a neutrondetection plate;

[0015]FIG. 11 is a neutron image detector using a superconducting tunneljunction device to detect the incident position of neutrons by means ofa superconducting sensor of an SIS structure with the intermediary ofphonons generated from a ¹⁰B enriched isotopic superconductor as aneutron detection plate;

[0016]FIG. 12 is a neutron image detector using a superconducting tunneljunction device to detect the incident position of neutrons by means ofa superconducting sensor of an SIS structure with the intermediary ofphonons generated from a ¹⁰B containing single LBO crystal as a neutrondetection plate;

[0017]FIG. 13 is a fast neutron image detector using a superconductingtunnel junction device to detect the incident position of neutrons bymeans of a superconducting sensor of an SIS structure with theintermediary of phonons generated from a hydrogen (H) containing plasticmaterial as a fast neutron detection plate;

[0018]FIG. 14 is a neutron image detector using a superconducting tunneljunction device to detect the incident position of neutrons by means ofa phonon detector device of a bolometer structure with the intermediaryof phonons generated from a ¹⁰B enriched isotopic superconductor as aneutron detection plate; and

[0019]FIG. 15 is a neutron image detector using a superconducting tunneljunction device to detect the incident position of neutrons by means ofa phonon detector device of a calorimeter type with the intermediary ofphonons generated from a ¹⁰B enriched isotopic superconductor as aneutron detection plate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLE 1

[0020] The first example of the invention as it relates to a photon,radiation and neutron detector is described below with reference toFIG. 1. In this example, MgB₂ is used as a superconductor having ahigher critical temperature than conventional superconductors such asNb. The superconductor MgB₂ can be prepared in two forms enriched in ¹⁰Band ¹¹B, respectively. The isotope effect realizes two superconductors¹⁰B and ¹¹B having different energy gaps. This effect was used tofabricate a five-layered superconducting tunnel junction devicecomprising in the order written an isotopic superconductor Mg¹⁰B₂ ofwide energy gap, an isotopic superconductor Mg¹¹B₂ of narrow energy gap,an insulation layer, an isotopic superconductor Mg¹¹B₂ of narrow energygap and an isotopic superconductor Mg¹⁰B₂ of wide energy gap. The Mg¹⁰B₂layers were each about 500 nm thick and the Mg¹¹B₂ layers were eachabout 50 nm thick. The insulation layer was about 2 nm thick. Theisotopic superconductor Mg¹¹B₂ of narrow energy gap formed aquasiparticle trapping layer which trapped the quasiparticles generatedfrom the isotopic superconductor Mg¹⁰B₂ of wide energy gap and thisenabled efficient detection of photons or radiations. Since thesuperconductor layer working as the detection medium and the trappinglayer were made of isotopic superconductors, they were easier to makethan the conventional Nb/Al layer and their continuity assured moreefficient device operation. The design of Example 1 allowed forfabrication of a radiation detector capable of measuring the energy ofradiations.

EXAMPLE 2

[0021] The second example of the invention as it relates to a neutrondetector is described below with reference to FIG. 2. Example 2 isidentical to Example 1 except for the use of an isotopic superconductorMg¹⁰B₂ containing the neutron converter boron (¹⁰B) as a constituentelement. By using the isotopic superconductor Mg¹⁰B₂ to detect theα-rays emitted from ¹⁰B having a large neutron absorptioncross-sectional area, we could fabricate a neutron detector using asuperconducting tunnel junction device to be capable of efficientneutron detection.

EXAMPLE 3

[0022] The third example of the invention as it relates to a neutrondetector is described below with reference to FIG. 3. In this example,an isotopic superconductor Mg¹⁰B₂ containing boron (B) as a constituentelement was used to fabricate a four-layered superconducting tunneljunction device comprising in the order written an isotopicsuperconductor Mg¹⁰B₂ of wide energy gap, an isotopic superconductorMg¹¹B₂ of narrow energy gap, an insulation layer and an isotopicsuperconductor Mg¹¹B₂ of narrow energy gap. Mg¹¹B₂ formed aquasiparticle trapping layer. Since the Mg¹¹B₂ on one side renderedinsensitivity to neutrons, the neutron detector of Example 3 wassensitive to neutrons only on the other side. The individual layers ofthe detector had the same thicknesses as in Example 1.

EXAMPLE 4

[0023] The fourth example of the invention as it relates to a neutrondetector is described below with reference to FIG. 4. In this example,an isotopic superconductor Mg¹⁰B₂ containing boron (B) as a constituentelement was used to fabricate a three-layered superconducting tunneljunction device comprising in the order written an isotopicsuperconductor Mg¹⁰B₂ of wide energy gap, an insulation layer and anisotopic superconductor Mg¹¹B₂ of narrow energy gap. Since the Mg¹¹B₂ onone side rendered insensitivity to neutrons, the neutron detector ofExample 3 was sensitive to neutrons only on the other side. Theindividual layers of the detector had the same thicknesses as in Example1.

EXAMPLE 5

[0024] The fifth example of the invention as it relates to a photon,X-ray and neutron detector is described below with reference to FIG. 5.In this example, an isotopic superconductor MgB₂ containing boron (B) asa constituent element has the isotope effect which realizes twosuperconductors having different energy gaps. This effect was used tofabricate a three-layered superconducting tunnel junction devicecomprising in the order written an Mg¹⁰B₂/Mg¹B₂ gradient superconductorwith a gradual compositional transition in the direction of thicknessfrom a superconductor enriched in ¹⁰B of the wider energy gap to asuperconductor enriched in ¹¹B of the narrower energy gap, an insulationlayer and an Mg¹⁰B₂/Mg¹¹B₂ gradient superconductor with a gradualcompositional transition in the direction of thickness from asuperconductor enriched in ¹⁰B of the wider energy gap to asuperconductor ¹¹B of the narrower energy gap. The two gradientsuperconductor layers were each about 500 nm thick and the insulationlayer was about 2 nm thick. The quasiparticles generated in eachgradient superconductor would migrate to the isotopic superconductor ofthe narrower energy gap, thereby allowing for efficient detection ofphotons, radiations or neutrons by the superconducting tunnel junction.

EXAMPLE 6

[0025] The sixth example of the invention as it relates to a neutronimage sensor is described below with reference to FIG. 6. In thisexample, an isotopic superconductor MgB₂ containing boron (B) as aconstituent element has the isotope effect which realizes twosuperconductors having different energy gaps. This effect was used tofabricate a three-layered superconducting tunnel junction devicecomprising in the order written an Mg¹⁰B₂/Mg¹¹B₂ gradient superconductorwith a gradual compositional transition in a two-dimensional plane froma superconductor enriched in ¹⁰B of the wider energy gap to asuperconductor enriched in ¹¹B of the narrower energy gap, an insulationlayer and an Mg¹⁰B₂/Mg¹¹B₂ gradient superconductor with a gradualcompositional transition in a two-dimensional plane from asuperconductor enriched in ¹⁰B of the wider energy gap to asuperconductor enriched in ¹¹B of the narrower energy gap. The twogradient superconductor layers were each about 500 nm thick and theinsulation layer was about 2 nm thick. On account of the Mg¹⁰B₂/Mg¹¹B₂gradient superconductor, different energy gaps, hence, varying pulsepeaks would be output depending upon the incident position of photons,radiations or neutrons; as a result, photons or radiations incident withspecified energy or neutrons emitting a specified energy of α-rays couldbe detected for their image at high position resolution. This designenables the fabrication of a photon, radiation and neutron imagedetector using a superconducting tunnel junction device.

EXAMPLE 7

[0026] The seventh example of the invention as it relates to a neutronimage sensor is described below with reference to FIG. 7. In thisexample, there is fabricated a five-layered superconducting tunneljunction device comprising in the order written an isotopicsuperconductor Mg¹⁰B₂ as a detection medium that is enriched in ¹⁰B ofwide energy gap, an Mg¹⁰B₂/Mg¹¹B₂ gradient superconductor with a gradualcompositional transition in a two-dimensional plane from asuperconductor enriched in ¹⁰B of the wider energy gap to asuperconductor enriched in ¹¹B of the narrower energy gap, an insulationlayer, an Mg¹⁰B₂/Mg¹¹B₂ gradient superconductor with a gradualcompositional transition in a two-dimensional plane from asuperconductor enriched in ¹⁰B of the wider energy gap to asuperconductor enriched in ¹¹B of the narrower energy gap, and the otherdetection medium made of Mg¹⁰B₂. The two layers of the isotopicsuperconductor Mg¹⁰B₂ enriched in ¹⁰B of wide energy gap were each 500nm thick, the gradient superconductor layers were each about 50 nmthick, and the insulation layer was about 2 nm thick. The Mg¹⁰B₂/Mg¹¹B₂gradient superconductors worked as quasiparticle trapping layers, sowhen the quasiparticles generated within Mg¹⁰B₂ were detected in thesuperconducting tunnel junction, different energy gaps, hence, varyingpulse peaks would be outputted depending upon the incident position ofphotons, radiations or neutrons; as a result, photons or radiationsincident with specified energy or neutrons emitting a specified energyof α-rays could be detected for their image at high position resolution.This design again enables the fabrication of a photon, radiation orneutron image detector using a superconducting tunnel junction device.

EXAMPLE 8

[0027] The eighth example of the invention as it relates to a radiationimage detector is described below with reference to FIG. 8. The isotopicsuperconductor Mg¹⁰B₂ enriched in ¹⁰B of wide energy gap has a differentenergy gap than the isotopic superconductor Mg¹¹B₂ enriched in ¹¹B ofnarrow energy gap. To take advantage of this effect, the isotopicsuperconductor Mg¹⁰B₂ of wide energy gap was used as a detection platewhich was provided with a phonon sensor at the center and the fourcorners in order to detect phonons generated in the plate which it wasilluminated with a radiation. The phonon sensor had a two-layeredstructure consisting of an insulation layer overlaid with the isotopicsuperconductor Mg¹¹B₂ enriched in ¹¹B of narrow energy gap. Both theintensity and the propagation time of signals from the phonon sensorswere both used to detect the incident position of a radiation. Thedetection plate made of the isotopic superconductor Mg¹⁰B₂ measured 2mm^(L)×2 mm^(W)×0.2 mm^(T); the Mg¹¹B₂ layer was 50 nm thick and theinsulation layer was 2 nm thick. This design enables the fabrication ofa radiation image detector using a superconducting tunnel junctiondevice. The energy of an incident radiation could be measured byanalyzing the output signal from each phonon sensor.

EXAMPLE 9

[0028] The ninth example of the invention as it relates to a neutronimage detector is described below with reference to FIG. 9. This exampleis identical to Example 8. Since the isotopic superconductor Mg¹⁰B₂containing the neutron converter boron (¹⁰B) as a constituent element isused as the neutron detection plate, α-particles emitted from ¹⁰B havinga large neutron cross-sectional area are detected in the isotopicsuperconductor Mg¹⁰B₂ layer formed in a thickness of 0.2 mm andefficient neutron detection can be accomplished by the neutron imagedetector of Example 9.

EXAMPLE 10

[0029] The tenth example of the invention as it relates to a neutronimage detector is described below with reference to FIG. 10. Thisexample is identical to Example 9, except that the phonon sensor has athree-layered structure consisting of the isotopic superconductor Mg¹¹B₂enriched in ¹¹B of narrow energy gap, an insulation layer and theisotopic superconductor Mg¹¹B₂ enriched in ¹¹B of narrow energy gap. Thephonon sensor having this configuration is capable of producing highersignal outputs than in Example 8 and, hence, the neutron image detectorof Example 9 has even better sensitivity than that of Example 8. Theabove-described design enables the fabrication of a neutron imagedetector using a superconducting tunnel junction device.

EXAMPLE 11

[0030] The eleventh example of the invention as it relates to a neutronimage detector is described below with reference to FIG. 11. Thisexample is identical to Example 9, except that the phonon sensor has anSIS structure consisting of a superconductor (S), an insulator (I) and asuperconductor (S). The SIS structure may be a Nb/Al/Al₂O₃/Al/Nbstructure. The phonon sensor having this configuration has a narrowerenergy gap and, hence, is capable of producing higher signal outputsthan in Example 8, provided that it operates at 0.4 K and below. Theabove-described design enables the fabrication of a neutron imagedetector using a superconducting tunnel junction device.

EXAMPLE 12

[0031] The twelfth example of the invention as it relates to a neutronimage detector is described below with reference to FIG. 12. In thisexample, a ¹⁰B containing single-crystal LBO mass (LiB₃O₅ or Li₂B₄O₇) isused as a neutron detection plate. In order to detect phonons generatedwhen it is illuminated with neutrons, the detection plate is providedwith a phonon sensor having a Nb/Al/Al₂O₃/Al/Nb structure as an SISstructure. This phonon sensor is provided at the center and the fourcorners of the detection plate and uses the intensity and thepropagation time of output signals to detect the incident position ofneutrons. The above-described design enables the fabrication of aneutron image detector using a superconducting tunnel junction device.

EXAMPLE 13

[0032] The thirteenth example of the invention as it relates to a fastneutron image detector is described below with reference to FIG. 13. Inthis example, a hydrogen (H) containing plastic material is used as afast neutron detection plate. In order to detect phonons due to thegeneration of protons (p) in the (n,p) reaction which occurs when it isilluminated with neutrons, the detection plate is provided with a phononsensor having a Nb/Al/Al₂O₃/Al/Nb structure as an SIS structure. Thisphonon sensor is provided at the center and the four corners of thedetection plate and uses the intensity and the propagation time ofoutput signals to detect the incident position of fast neutrons. Thehydrogen (H) containing plastic detection plate measures 2 mm^(L)×2mm^(W)×0.2 mm^(T). The above-described design enables the fabrication ofa fast neutron image detector using a superconducting tunnel junctiondevice.

EXAMPLE 14

[0033] The fourteenth example of the invention as it relates to a 2Dneutron image detector is described below with reference to FIG. 14.This example is the same as Example 9, except that a bolometer device isused as the phonon sensor. The bolometer device is a neutron-producingnuclear transmutation Ge bolometer. The device is a sensor capable ofhighly sensitive detection of temperature elevations due to phononsignals through measurement of changes in resistance. Theabove-described design enables the fabrication of a neutron imagedetector using a superconducting tunnel junction device.

EXAMPLE 15

[0034] The fifteenth example of the invention as it relates to a 2Dneutron image detector is described below with reference to FIG. 15.This example is the same as Example 9, except that a calorimeter deviceis used as the phonon sensor. The calorimeter device is a transitionedge (TES) device using a tungsten superconductor. The device is asensor capable of highly sensitive detection of temperature elevationsdue to phonon signals through measurement of changes in resistance. Theabove-described design enables the fabrication of a neutron imagedetector using a superconducting tunnel junction device.

What is claimed is:
 1. A photon or radiation detector using asuperconducting tunnel junction device which, taking advantage of theisotopic effect providing two superconductors with different energygaps, has a five-layered structure comprising in the order written anisotopic superconductor of wide energy gap, an isotopic superconductorof small energy gap, an insulation layer, an isotopic superconductor ofnarrow energy gap and an isotopic superconductor of wide energy gap. 2.A neutron detector using a superconducting tunnel junction device which,taking advantage of the isotopic effect of a boron (B) containingsuperconductor which provides the superconductor with different energygaps, has a five-layered structure comprising in the order written anisotopic superconductor enriched in ¹⁰B of wide energy gap, an isotopicsuperconductor enriched in ¹¹B of small energy gap, an insulation layer,an isotopic superconductor enriched in ¹¹B of narrow energy gap and anisotopic superconductor enriched in ¹⁰B of wide energy gap.
 3. A neutrondetector using a superconducting tunnel junction device which, takingadvantage of the isotopic effect of a boron (B) containingsuperconductor which provides the superconductor with different energygaps, has a four-layered structure comprising in the order written anisotopic superconductor enriched in ¹⁰B of wide energy gap, an isotopicsuperconductor enriched in ¹¹B of small energy gap, an insulation layerand an isotopic superconductor enriched in ¹¹B of narrow energy gap. 4.A neutron detector using a superconducting tunnel junction device which,taking advantage of the isotopic effect of a boron (B) containingsuperconductor which provides the superconductor with different energygaps, has a three-layered structure comprising in the order written anisotopic superconductor enriched in ¹⁰B of wide energy gap, aninsulation layer and an isotopic superconductor enriched in ¹¹B of smallenergy gap.
 5. A photon, radiation or neutron detector using asuperconducting tunnel junction device which, taking advantage of theisotopic effect of a boron (B) containing superconductor which providesthe superconductor with different energy gaps, has a three-layeredstructure comprising in the order written a gradient superconductor witha gradual compositional transition in the direction of thickness from anisotopic superconductor enriched in ¹⁰B of wide energy gap to anisotopic superconductor enriched in ¹¹B of narrow energy gap, aninsulation layer and a gradient superconductor with a gradualcompositional transition in the direction of thickness from an isotopicsuperconductor enriched in ¹¹B of narrow energy gap to an isotopicsuperconductor enriched in ¹⁰B of wide energy gap.
 6. A photon,radiation or neutron image detector using a superconducting tunneljunction device which, taking advantage of the isotopic effect of aboron (B) containing superconductor which provides the superconductorwith different energy gaps, has a three-layered structure comprising inthe order written a gradient superconductor serving as a detection platewith a gradual compositional transition in a two-dimensional plane froman isotopic superconductor enriched in ¹⁰B of wide energy gap to anisotopic superconductor enriched in ¹¹B of narrow energy gap, aninsulation layer and a gradient superconductor with a gradualcompositional transition in a two-dimensional plane from an isotopicsuperconductor enriched in ¹⁰B of wide energy gap to an isotopicsuperconductor enriched in ¹¹B of narrow energy gap, said image detectorperforming image detection by taking advantage of the fact that thepulse wave height to be outputted varies with the incident position ofphotons, radiations or neutrons.
 7. A photon, radiation or neutron imagedetector using a superconducting tunnel junction device which, takingadvantage of the isotopic effect of a boron (B) containingsuperconductor which provides the superconductor with different energygaps, has a five-layered structure comprising in the order written anisotopic superconductor serving as a detection plate which is enrichedin ¹⁰B of wide energy gap, a gradient superconductor serving as aquasiparticle trapping layer with a gradual compositional transition ina two-dimensional plane from an isotopic superconductor enriched in ¹⁰Bof wide energy gap to an isotopic superconductor enriched in ¹¹B ofnarrow energy gap, an insulation layer, a gradient superconductorserving as a quasiparticle trapping layer with a gradual compositionaltransition in a two-dimensional plane from an isotopic superconductorenriched in ¹⁰B of wide energy gap to an isotopic superconductorenriched in ¹¹B of narrow energy gap, and an isotopic superconductorserving as a detection plate which is enriched in ¹⁰B of wide energygap, said image detector performing image detection by taking advantageof the fact that the pulse wave height to be outputted varies with theincident position of photons, radiations or neutrons.
 8. A radiationimage detector using a superconducting tunnel junction device which,taking advantage of the isotopic effect providing two superconductorswith different energy gaps, uses an isotopic superconductor of wideenergy gap as a detection plate, said detection plate being providedwith at least two phonon sensors each comprising an insulation layeroverlaid with an isotopic superconductor of narrow energy gap in orderto detect phonons as they are generated upon incidence of a radiation,either the intensity or propagation time of a signal from each of saidphonon sensors or both such signal intensity and propagation time beingused to detect the incident position of photons or a radiation.
 9. Aneutron image detector using a superconducting tunnel junction devicewhich, taking advantage of the isotopic effect of a boron (B) containingsuperconductor which provides two superconductors with different energygaps, uses an isotopic superconductor enriched in ¹⁰B of wide energy gapas a neutron detection plate, said detection plate being provided withat least two phonon sensors each comprising an insulation layer overlaidwith an isotopic superconductor enriched in ¹¹B of narrow energy gap inorder to detect phonons resulting from the generation of α-rays whichoccurs upon incidence of neutrons, either the intensity or propagationtime of a signal from each of said phonon sensors or both such signalintensity and propagation time being used to detect the incidentposition of neutrons.
 10. A neutron image detector using asuperconducting tunnel junction device which, taking advantage of theisotopic effect of a boron (B) containing superconductor which providestwo superconductors with different energy gaps, uses an isotopicsuperconductor enriched in ¹⁰B of wide energy gap as a neutron detectionplate, said detection plate being provided with at least two phononsensors each comprising in the order written an isotopic superconductorenriched in ¹¹B of narrow energy gap, an insulation layer and anisotopic superconductor enriched in ¹¹B of narrow energy gap in order todetect phonons resulting from the generation of α-rays which occurs uponincidence of neutrons, either the intensity or propagation time of asignal from each of said phonon sensors or both such signal intensityand propagation time being used to detect the incident position ofneutrons.
 11. A neutron image detector using a superconducting tunneljunction device which uses a ¹⁰B enriched isotopic superconductor as aneutron detection plate, said detection plate being provided with atleast two phonon sensors each comprising in the order written a metalsuperconductor, an insulation layer and a metal superconductor or ametal superconductor of wide energy gap provided with a quasiparticletrapping layer, a metal superconductor of narrow energy gap, aninsulation layer, a metal superconductor of narrow energy gap and ametal superconductor of wide energy gap in order to detect phononsresulting from the generation of α-rays which occurs upon incidence ofneutrons, either the intensity or propagation time of a signal from eachof said phonon sensors or both such signal intensity and propagationtime being used to detect the incident position of neutrons.
 12. Aneutron image detector using a superconducting tunnel junction devicewhich uses a ¹⁰B containing single crystal as a neutron detection plate,said detection plate being provided with at least two phonon sensorseach comprising in the order written a metal superconductor, aninsulation layer and a metal superconductor or a metal superconductor ofwide energy gap provided with a quasiparticle trapping layer, a metalsuperconductor of narrow energy gap, an insulation layer, a metalsuperconductor of narrow energy gap and a metal superconductor of wideenergy gap in order to detect phonons resulting from the generation ofα-rays which occurs upon incidence of neutrons, either the intensity orpropagation time of a signal from each of said phonon sensors or bothsuch signal intensity and propagation time being used to detect theincident position of neutrons.
 13. A fast neutron image detector using asuperconducting tunnel junction device which uses a hydrogen (H)containing material as a neutron detection plate, said detection platebeing provided with at least two phonon sensors each comprising in theorder written a metal superconductor, an insulation layer and a metalsuperconductor or a metal superconductor of wide energy gap providedwith a quasiparticle trapping layer, a metal superconductor of narrowenergy gap, an insulation layer, a metal superconductor of narrow energygap and a metal superconductor of wide energy gap in order to detectphonons resulting from the generation of protons (p) which occurs uponincidence of neutrons, either the intensity or propagation time of asignal from each of said phonon sensors or both such signal intensityand propagation time being used to detect the incident position of fastneutrons.
 14. The neutron image detector according to any one of claims9-13 which uses a bolometer device as the phonon sensor.
 15. The neutronimage detector according to any one of claims 9-13 which uses acalorimeter device as the phonon sensor.